Method and apparatus for recovering fine gold from low grade ores

Abstract

Recovery of gold fines from gold-bearing ores is achieved by flowing an aqueous slurry of particulate gold-bearing ore over a sluice supporting a mat of magnetically susceptible particulate material, which preferably includes the magnetite content of the ore or a quantity of magnetite added to the ore, the mat being disposed over a sheet of magnetic material in which magnetic poles extending across the sluice and alternate in polarity at spaced intervals along the length of the sluice.

I claim: 
     
       1. The method of recovering fine gold from gold-bearing ore, comprising flowing a liquid slurry of particulate gold-bearing ore over a porous mat of magnetically susceptible particulate material overlying a flexible sheet of magnetic material arranged in rows of alternating polarity spaced apart in the direction of slurry flow, each row extending perpendicular to the direction of slurry flow. 
     
     
       2. The method of claim 1 wherein the layer of magnetically susceptible particulate material includes magnetite. 
     
     
       3. Apparatus for recovering fine gold from gold-bearing ore, comprising: a) a sluice having a bottom and lateral side walls and defining longitudinal ends of the sluice,   b) a flexible sheet of magnetic material supported on the sluice bottom and arranged in rows of alternating polarity extending across the sluice bottom and spaced apart in the direction of the flow through the sluice, and   c) a porous mat of magnetically susceptible particulate material overlying the magnetic material and for trapping fine particles of gold.   
     
     
       4. The apparatus of claim 3 wherein the layer of magnetically susceptible particulate material includes magnetite.